一. 获取当前系统时间和日期并格式化输出:import java.util.Date;
import java.text.SimpleDateFormat;public class NowString {
public static void main(String[] args) {
SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");//设置日期格式
System.out.println(df.format(new Date()));// new Date()为获取当前系统时间
}
}二. 在数据库里的日期只以年-月-日的方式输出，可以用下面两种方法：1、用convert()转化函数：String sqlst = "select convert(varchar(10),bookDate,126) as convertBookDate from roomBook where bookDate between '2007-4-10' and '2007-4-25'";System.out.println(rs.getString("convertBookDate"));2、利用SimpleDateFormat类：先要输入两个java包：import java.util.Date;
import java.text.SimpleDateFormat;然后：定义日期格式：SimpleDateFormat sdf = new SimpleDateFormat(yy-MM-dd);sql语句为：String sqlStr = "select bookDate from roomBook where bookDate between '2007-4-10' and '2007-4-25'";输出：System.out.println(df.format(rs.getDate("bookDate")));************************************************************java中获取当前日期和时间的方法import java.util.Date;
import java.util.Calendar; import java.text.SimpleDateFormat; public class TestDate{
public static void main(String[] args){
Date now = new Date();
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");//可以方便地修改日期格式String hehe = dateFormat.format( now );
System.out.println(hehe); Calendar c = Calendar.getInstance();//可以对每个时间域单独修改int year = c.get(Calendar.YEAR);
int month = c.get(Calendar.MONTH);
int date = c.get(Calendar.DATE);
int hour = c.get(Calendar.HOUR_OF_DAY);
int minute = c.get(Calendar.MINUTE);
int second = c.get(Calendar.SECOND);
System.out.println(year + "/" + month + "/" + date + " " +hour + ":" +minute + ":" + second);
}
}有时候要把String类型的时间转换为Date类型，通过以下的方式，就可以将你刚得到的时间字符串转换为Date类型了。SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");java.util.Date time=null;
try {time= sdf.parse(sdf.format(new Date()));} catch (ParseException e) {e.printStackTrace();
}